A very high strength swivel anchor for holding relatively heavy weights on substrates, such as gypsum board, is disclosed in U.S. Pat. No. 9,039,338, issued on May 26, 2015, to the same assignee as the present invention, with the disclosure thereof being entirely included herein by reference thereto.
A specific structure is shown and described in the aforementioned patent of a collapsed structure of two swivably connected anchor arms for insertion into a minimal size insertion aperture in a substrate, such as a wall. The connected arms are remotely swivelable in a plane parallel to the substrate to effectively at least double load bearing contact of the anchor arms with the substrate in a full 180° range. To ensure such full range a swivel stop on the anchor arms is configured to prevent the arms of the anchor from moving beyond an optimum expanded position of perpendicular intersection of the arms. There is however no mechanism or structure which may serve to prevent the anchor from inadvertently retracting from the optimum position. Unseen elements, such as studs, wiring, pipes and the like may unknowingly cause a swiveling retraction of the anchor arms from the fully extending position, thereby reducing holding strength. Since anchors for holding objects to substrates are generally used in applications wherein the other side of the substrate, such as a wall, is both inaccessible and out of view of the installer, such deviations of the anchor arms from optimum expansion, such as by retraction of the arms from the optimum expansion (e.g., with abutting contact of the opened arms with obstructions, such as wall studs), are possible without knowledge of the installer.